Matsya Purana — The Syamantaka Jewel Episode and the Vrishni–Sainya Genealogies
अश्विन्यां च ततः पुत्राः पृथुर् विपृथुरेव च अश्वत्थामा सुबाहुश्च सुपार्श्वकगवेषणौ //
aśvinyāṃ ca tataḥ putrāḥ pṛthur vipṛthureva ca aśvatthāmā subāhuśca supārśvakagaveṣaṇau //
And from Aśvinī, thereafter, sons were born—Pṛthu and Vipṛthu; Aśvatthāmā and Subāhu; and also Supārśvaka and Gaveṣaṇa.
Nothing directly—this verse is a genealogical register, naming descendants born from Aśvinī rather than describing cosmic dissolution or the flood narrative.
Indirectly: dynastic catalogues in the Matsya Purana frame dharma through lineage memory—preserving ancestry legitimizes royal succession and supports the householder ideal of maintaining family continuity and reputation.
None explicitly; the verse is purely nominative (a list of sons). Any Vastu or ritual rules belong to other thematic chapters, not this genealogical segment.